DOE OSTI2020
K4Ag2Sn3S9O2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 1-coordinate geometry to six S2- and one O2- atom. There are a spread of K–S bond distances ranging from 3.28–3.48 Å. The K–O bond length is 2.80 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to four S2- and three O2- atoms. There are two shorter (3.39 Å) and two longer (3.44 Å) K–S bond lengths. There are two shorter (2.69 Å) and one longer (2.77 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded in a 8-coordinate geometry to four S2- and four O2- atoms. There are two shorter (3.24 Å) and two longer (3.36 Å) K–S bond lengths. There are a spread of K–O bond distances ranging from 2.72–3.07 Å. In the fourth K1+ site, K1+ is bonded in a 1-coordinate geometry to six S2- and two O2- atoms. There are four shorter (3.28 Å) and two longer (3.35 Å) K–S bond lengths. There are one shorter (2.79 Å) and one longer (3.09 Å) K–O bond lengths. In the fifth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.23–3.67 Å. In the sixth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.18–3.55 Å. There are two inequivalent Ag3+ sites. In the first Ag3+ site, Ag3+ is bonded in a trigonal planar geometry to three S2- atoms. There are a spread of Ag–S bond distances ranging from 2.45–2.57 Å. In the second Ag3+ site, Ag3+ is bonded to four S2- atoms to form AgS4 tetrahedra that share corners with four SnS4 tetrahedra. There are a spread of Ag–S bond distances ranging from 2.52–2.62 Å. There are three inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one AgS4 tetrahedra and corners with two SnS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.37–2.49 Å. In the second Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share corners with two equivalent AgS4 tetrahedra and corners with two SnS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.37–2.47 Å. In the third Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one AgS4 tetrahedra and corners with two SnS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.37–2.49 Å. There are nine inequivalent S2- sites. In the first S2- site, S2- is bonded to three K1+ and two Sn4+ atoms to form distorted edge-sharing SK3Sn2 trigonal bipyramids. In the second S2- site, S2- is bonded in a 5-coordinate geometry to three K1+ and two Sn4+ atoms. In the third S2- site, S2- is bonded in a 5-coordinate geometry to three K1+, one Ag3+, and one Sn4+ atom. In the fourth S2- site, S2- is bonded in a 2-coordinate geometry to two K1+, one Ag3+, one Sn4+, and two O2- atoms. There are one shorter (3.34 Å) and one longer (3.40 Å) S–O bond lengths. In the fifth S2- site, S2- is bonded in a 6-coordinate geometry to four K1+, one Ag3+, and one Sn4+ atom. In the sixth S2- site, S2- is bonded in a 6-coordinate geometry to two K1+, two Ag3+, one Sn4+, and one O2- atom. The S–O bond length is 2.93 Å. In the seventh S2- site, S2- is bonded in a 5-coordinate geometry to three K1+, one Ag3+, and one Sn4+ atom. In the eighth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two equivalent K1+ and two Sn4+ atoms. In the ninth S2- site, S2- is bonded in a 5-coordinate geometry to two K1+, one Ag3+, one Sn4+, and one O2- atom. The S–O bond length is 3.48 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three K1+ and two equivalent S2- atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three K1+ and two equivalent S2- atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two K1+ and two S2- atoms.